Because of the availability of the Global Positioning System (GPS), vehicles rely on satellite navigation systems for position information. However, with the increasing reliance on these satellite navigation systems, the vehicles become increasingly vulnerable to GPS failure and/or spoofing of a satellite signal. Without an alternative system to a GPS-based navigator, the loss of a GPS signal and the commensurate loss of position information can lead to position inaccuracy which can result in mission failure and, in a worst case scenario, the loss of a platform and life. To solve the problem of operating in a GPS-denied environment, some systems integrate GPS with a variety of supplemental sensors such as inertial sensors, radio navigation aids, optical scene correlators (e.g. Digital Scene Matching Correlator (DSMAC)), radar/terrain correlators (e.g., Precision Terrain Aided Navigation (PTAN)), and the like. However, these supplemental sensors can be prohibitively expensive and unavailable for certain vehicles.